Brake for crawler tracks



Nov. 20, 1945. R. Q. ARMlNGToN BRAKE FOR CRAWLER TRACK Filed Feb. 18, 1944 2 She'eiS-Sheet l rlllllllilllllll ATT 01W/5K5 1 Nov. 20, 1945. R. Q. ARMINGTON 2,389,289

BRAKE FOR CRAWLER TRACK f3.4 vMoNo Q. Amm/@Tow l ATTORNEYS Patented Nov. 20, 1945 lUNITED STATES PATENT oFi-'lcE BRAKE FOR CRAWLER TRACKS Raymond Q. Armington, Shaker Heights, Ohio, assignor to The Euclid Road Machinery Co., Euclid, Ohio, a corporation of Ohio Application February 18, 1944, Serial No. 522,886

1 Claim.

This invention relates to improvements in brakes for endless crawler tracks.

An object of the present invention is to provide braking means for decelerating, stopping or holding an endless crawler 4track device. My invention contemplates the application of the brake to various types of endless tracks and the application of the brake by power means, manually or otherwise, as will appear in the vfollowing description. The essential features of my device will be summarized in the appended claim.

In the drawings:

Fig. 1 is a side elevational view of my invention applied to one type of endless crawler track;

Figs. 2, 3 and 4 are sectional views taken along similarly numbered lines of Fig. l;

Fig. 5 is a top plan view of a single track shoe of the device oi' Figs. 1 to 4, with all connected parts removed.

My invention is applicable to many types of endless crawler track devices and while I have chosen to illustrate the same herein as applied to two different types of track, this should be regarded as illustrative only and in no sense as limiting .the invention to those two types of track.

In the modication of Figs. 1 to 5 I have shown the brake as applied to a crawler track of the general type disclosed in the copending application of Stewart F. Armington, Serial-No. 493,555, led July 5, 1943. In this type Aof track a frame generally indicated at i supports endless guide rail means il of generally elliptical form about which the endless track moves. The track itself comprises a plurality of shoes i 2 connected together by hinge pins i3 to provide an endless track. Each shoe supports a roller I4 and these rollers engage the guide rail i i.

Briefly, the frame Il! comprises a box beam extending longitudinally through the center of the device, this box beam having parallel side walls Illa, a bottom wall I0b and a top wall of inverted V-forrn il'lc. The guide rail II is in two paralle1 portions spaced apart laterally as best seen in Fig. 4 and so constructed that inside and outside ilanges on the guide rail serve to retain the rollers in place. Suitable supporting and stifiening plates l5 are connected with the upper run of the guide rail and supporting and dirt-shedding plates i6 are connected between the frame and the lower run of the guide rail. A sleeve I1 extends transversely through the frame at a central location so that the frame may have a trunnion mounting on the vehicle which is to be carried by the crawler track.

Each of the shoes l2 comprises a slightly curved bottom plate I 8 for engaging'the ground with a. centrally located tubular member i9 welded at one end of the shoe and laterally spaced tubular members 20 welded at the other end, these obviously forming intertting hinge parts which are connected together, when the track is assembled, by the hinge pins i3 which pass through suitable bores in the tubes i9 and 2li, as indicated in Fig. 5. Each shoe is provided with parallel upstanding side walls 2i which are drilled at 22 to receive the shaft 23 upon which the rollers i4 are mounted. Stiftening members 24 are added where necessary. Means on the shoe for application of a brake is supplied by a pair of plates 25 extending respectively along the outer side portions of the shoe, each of these `plates being bent downwardly at the ends 25a and each of the plates being welded to the parts i8, I9, 2li, 2l and 24 of the shoe.

The braking means comprises a pair of brake shoes 26 and 21, preferably elongated in a fore and aft direction so as to provide suilicient braking surface 26a and 21a respectively to engage a plurality of the plates 25 of several shoes I2. Means is provided for coincidentally pressing downward on shoes 26 and 21 and, where the shoes are elongated, for pressing down coincidentally on both ends of a brake shoe. 'Ihis means may be actuated manually or by power, as will presently appear.

A sleeve bearing 28 rigidly mounted crosswise in the frame l0 oscillatably supports a shaft 29 which has splined connections at its opposite ends with bell cranks 30 and 3i, which have shorter arms 30a and 3la respectively which are connected with the forward ends of brake shoes 26 and 21 by pins 30h and 3|b respectively. Near the rear end of the shoes a. sleeve bearing 32 is rigidly mounted in frame I0 parallel to sleeve bearing 28. A shaft 33 is mounted for oscillation in this sleeve bearing and at one end has a splined connection with bell crank 34, the shorter arm of which, 34a, is connected to brake shoe 26 by pin 34D. The opposite end of shaft 33 has a splined connection with a short bifurcated lever 35 which by means of pin 35a is connected tothe rear end of brake shoe 21. As best seen in Fig. 2 the upper ends of the longer arms of the bell cranks 30 and 34 are connected together by parallel links 36 so as to cause them to move in unison. Means connected with the longer arm 3lc of bell crank 3l serves when operated to 34 and the short lever 35.

Power means is here shown for applying the brake shoe to the endless track This means comprises a cylinder Il, one end of which is provided with a clevis 38 which is pivotally connected by pin I! with a mounting rod ,40 which has a threaded connection in `bracket 4i rigidly mounted on frame i0. Cylinder 31 is fitted with a reciprocable piston 31a having a piston rod 31h, the free end oi' which is fittedA with a clevis 42. 'I'his clevis is connected by pin 43 with bell crank arm llc and with the clevis end a of a rod M whose end opposite the clevis a has threaded enlsement with a nut Il, which in turn has a loose bearing in bracket I6 which is rigidly connected tothe main frame IU. Means is provided for actuating the piston 31a which might be double acting but which in the present case is single acting by means of pressureiluid supplied at the right-hand end of cylinder I1 as viewed in Fig. 2 through conduit 4l which is connected to a source o! pressure fluid, not shown. If the vehicle sup- Y ported on the endless track were a trailer behind a tractor device, obviously the control of iluid flow through conduit 41 might well be placed within the control of the operator oi' the tractor device, if desired. such control arrangements be- -ing well known in this art. A spring 48 is supplied ior returning the piston 31a toward the right as viewed in Fig. 2 when premura uid is exhausted though conduit 4T by suitable control means.

The purpose of nut 4I is to manually apply the brake shoes it so desired and in the absence of power for the cylinder Il. For instance, if the endless track device shown were attached to a non-driving vehicle, as a trailer or the like, then it this non-driving vehicle were disconnected from its tractor device it might be desirable to set the brakes. In this case the nut 45 would be turned on the rod M so as to move the bell cranks 8l and Il in a counterclockwise direction as viewed in Fig. 1, which of course corresponds to similar movement of bell crank Il and lever arm '35. Obviously the nut Il may be turned sufficiently to press the brake shoes 2l and 21 against the plates 2B oi' several shoes oi' the endless track which are in engagement with the ground or other supporting surface. In a similar manner, when th'e parts are in the position of Figs. 1 and 2 with the application oi' pressure iluid through conduit 41, the brakes may be similarly applied and upon release of the pressure iluid` spring I8 will cause return movement of piston 31a so as to release the brakes. The upwardly inclined ends of brake shoes 26 and 21 coact with the inclined ends of the plates 25 to provide easy engagement between the brake shoes and the track shoes when the latter are moving.

In my device I have shown a brake shoe connected with the frame of the crawler track device and adapted to be moved downwardly 1n frictional engagement with a portion of the endless track which is in engagement with the ground. Th'us that portion of the endless track may be held i'rictionally between the brake shoe and the ground so as to stop movement ofthe crawler track. It is obvious that this principle is equally applicable to a bogie-wheel type track or to an endless flexible track or any other type of end less track where a portion thereof may be gripped between the ground and a brake sh'oe carried by the frame.

What I claim is:

In combination, a frame having guide rail means substantially parallel to the ground, an endless crawler track on said frame having a lower run extending between said rail means and the ground, said track comprising a plurality of shoes hinged together, each of said shoes h'aving a roller engaging said rail means. a pair ofv substantially parallel brake shoes carried by said frame above said lower run of said track, said brake shoes being adapted to engage the shoes of said track on opposite sides thereof, lever means for moving each of said brake shoes down wardly, and power means operatively connected wi 'said lever means for actuating both of said brake shoes coincidentally in track-engaging direction.

RAYMOND Q. ARMINGTON. 

